A Date class which can consume and produce dates in SQL Date format.
The SQL date format represents a date as yyyy-mm-dd. Note that this date format only deals with year, month and day values. There are no values for hours, minutes, seconds.
This contrasts with regular java.util.Date values, which include time values for hours, minutes, seconds, milliseconds.
Time points are handled as millisecond values - milliseconds since the epoch, January 1st 1970, 00:00:00.000 GMT. Time values passed to the java.sql.Date class are "normalised" to the time 00:00:00.000 GMT on the date implied by the time value.